Stone wool

Abstract

The invention relates to stone wool formed from stone melt and consisting of 70 to 90% by weight stone wool fibers having diameters of up to 5 mu m, 0 to 5% by weight stone wool fibers having diameters above 5 mu m, and 10 to 25% by weight shot having a diameter of at least 63 mu m, and in which the average diameter of the fibers is from 1 to 4 mu m, the ratio of average fiber length:average diameter is 1,000 to 3,000, wherein the stone wool has a density from 12 to 85 kg/m3 and thermal conductivity lambda values from 30 to 40 mW/m DEG K at 10 DEG C.

We claim: 
     
       1. Stone wool formed from stone melt and consisting of 75 to 90% by weight stone wool fibers and 10 to 25% by weight shot having diameters of at least 63 μm, and in which the average diameter of the fibers is from 1 to 4 μm, the ratio of average fiber length:average diameter is 1,000 to 3,000, wherein the density of the stone wool is from 12 to 85 kg/m 3  and wherein the thermal conductivity Lambda of the stone wool is from 30 to 40 mW/m°K at 10° C. and wherein the stone wool must have a relationship between density and Lambda as set out in the following table:   ______________________________________
               Maximum  Minimum
Lambda         Density  Density
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40             16       12
38             18       13
36             22       15
35             24       18
34             29       20
33             33       23
32             40       28
31             55       38
30             85        50,
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     intermediate values being obtainable by interpolation.   
     
     
       2. Stone wool according to claim 1 in which the amount of fibers having diameters of up to 3.5 μm is 75 to 88%. 
     
     
       3. Stone wool according to claim 2 in which the amount of fibers having diameters of up to 3.5 μm is 77 to 83%. 
     
     
       4. Stone wool according to claim 3 in which the amount of shot having diameters of at least 63 μm is from 15 to 22%. 
     
     
       5. Stone wool according to claim 2 in which the amount of shot having diameters of at least 63 μm is from 15 to 22%. 
     
     
       6. Stone wool according to any one of claims 2 or 3 in which the amount of fibers having diameters above 5 μm is 0 to 6% based on cumulative length based measurement. 
     
     
       7. Stone wool according to claim 6 in which the amount of shot having diameters of at least 63 μm is from 15 to 22%. 
     
     
       8. Stone wool according to claim 1 in which the amount of shot having diameters of at least 63 μm is from 15 to 22%. 
     
     
       9. Stone wool according to claim 1 in which the amount of shot having diameters greater than 250 μm is 0 to 2%. 
     
     
       10. Stone wool according to claim 1 in which the amount of shot having diameters greater than 250 μm is 0 to 1%. 
     
     
       11. Stone wool according to claim 1 in which the average diameter of the fibers is from 2.0 to 3.5 μm. 
     
     
       12. Stone wool according to claim 1 in which the ratio of average fiber length to average diameter is from 1,100 to 2,000. 
     
     
       13. Stone wool according to claim 12 in which the ratio of average fiber length to average diameter is from 1,200 to 1,600. 
     
     
       14. Stone wool according to claim 1 wherein the fibers have a tensile strength of from 6 to 14 kN/m 2 . 
     
     
       15. Stone wool according to claim 1 in which the stone is selected from the group consisting of rock, slag, diabase and basalt. 
     
     
       16. Stone wool according to claim 1 further containing a bonding agent. 
     
     
       17. Stone wool according to claim 16, wherein said stone wool is formed into bonded stone wool batts.